in tetrahydrofuran Heating; Yield given;

in dichloromethane XeF2 added in small portions under Ar to a soln. of selenide in CH2Cl2 at -20°C, stirred for 30 min, the acetylene added, stirred for 1 h at -20°C and for 1 h at room temp.; precipitate separated, washed with n-pentane, solvent removed under vacuum, crude product purified by column chromy., elem. anal.;

18-crown-6 ether; cesium fluoride in acetonitrile T=20°C; 8 h;